by Bob Pennell
When the tanks were removed from the car, there had been no leaks. Upon inspection, there appeared to be only superficial rusting on the bottom. So, I wire brushed and sanded to bare metal, then metal prepped before priming and painting. The interiors were coated thoroughly with Bill Hirsch gas tank sealer, and the tanks reinstalled in the car.
As soon as the tanks were filled with gas, the left side began to leak at the rate of about one cup per hour. Suspecting a loose connection at the balance pipe, I removed the trim panels and felt around under the hose connections, but no leaks were evident here. So, out came the left side tank, and external inspection uncovered no obvious point of leakage. The tank was dried out, and another application of the Hirsch sealer added. This time, the tank was partially filled with gas and allowed to sit for several days outside of the car. No leaks, so back in the car it went and everything was buttoned up in the trunk area.
Several weeks elapsed, and then the dripping started again, this time at a slower rate than before. Upon removal a second time, a pinhole was evident at the bottom of the tank where a small amount of sealer also had bled through.
Enough fooling around, I thought, and the tank was sanded down to bare metal and the entire bottom encased with fiberglass cloth and epoxy resin, then repainted and reinstalled. So far so good, no leaks the third time around. The right side will probably start any day now, the way my luck seems to run. The point of this is simply if you observe any surface rust at all on the bottom of the tank, don’t mess around with glass!
Editors note: Pinholes can be soldered or brazed and then sealed with many of the new gas tank sealers now on the market.